Billie Lourd rings in 25 with rainbow-themed pool party

Who doesn't love a themed party?

Billie Lourd and a few friends hit the pool over the weekend to celebrate her birthday, and, naturally, had a few rainbow-themed props on hand. 

The actress, who turned 25 Monday, threw a colorful bash complete with water slides and a photo booth. Pals including Colton Haynes joined Lourd for the party. 

All of which made for some great social media snapshots.

Haynes also shared a photo, along with a sweet birthday message. 

"Too much fun celebrating @praisethelourd 's Bday :) Rainbows, water slides, & food trucks...the best :) Happy Bday boo!!!" he wrote. 

Lourd's stepdad Bruce Bozzi also attended the party. 

The day before, Lourd also took a moment to remember her mother in a special post, thanking Disney for making Fisher "the ultimate Disney combo: a princess and now a legend." Disney inducted Fisher at the Legends Awards ceremony at the D23 Expo Friday. 

Monday marks Lourd's first birthday without her mother or grandmother. Carrie Fisher and Debbie Reynolds died within a day of each other in December.